The present disclosure relates to electronic apparatuses and image forming apparatuses and particularly relates to a technique for detecting an object with a pyroelectric infrared sensor.
In a general image forming apparatus as an example of an electronic apparatus, a fixing roller of a fixing section configured to fix an image on a recording paper sheet is kept above a certain temperature also during standby for the formation of an image. Thus, an image forming operation can be started in a short time upon receipt of an operator's command to execute the formation of the image. This heating of the fixing section consumes the most power in an image formation process and, therefore, its power consumption is required to be reviewed. As an example of a solution to this, there is proposed an image forming apparatus equipped with a human body sensor. In this image forming apparatus, the heating of the fixing section is started after the detection of a human body by the human body sensor and, thus, the fixing section can be heated by the use of the time from the detection of the human body to the operator's reaching an operating section of the apparatus. Therefore, the fixing temperature during standby can be set lower than in apparatuses equipped with no human body sensor. Furthermore, when any human body becomes undetected by the human body sensor, the image forming apparatus is shifted from a normal mode capable of immediate formation of an image to a sleep mode capable of power saving. Thus, a heater configured to heat the fixing section can be deactivated at an appropriate time to reduce power consumption.